Eighteen months ago, it was a crumbling Truman-era motel used as a homeless shelter, so decrepit that some units were uninhabitable and the faucets spewed brown water.

Now, La Mesita Family Homeless Shelter has become La Mesita Apartments, a modern four-story complex looming over the racks near the Tempe border.

The project at 2254 W. Main St. is the most ambitious undertaking ever launched by A New Leaf, a multipurpose social-service agency born in Mesa 43 years ago.

It makes its public debut in a dedication ceremony 1 p.m. Monday, March 31. Officials from the city, A New Leaf and the Arizona Department of Housing are expected to speak.

The state housing department is involved because in 2012 it approved A New Leaf's application for a special kind of funding to make the units affordable for people with low incomes. Under legislation signed by President Ronald Reagan, investors get tax credits if they finance low-income housing.

Several other such projects have been recently completed, are under construction or are being applied for in Mesa. The next round of tax-credit approvals is expected this spring.

Torrie Taj, chief operating officer for A New Leaf, said there is an all but insatiable demand for affordable workforce housing. The 80 units at La Mesita are filling as soon as they become available.

Taj said La Mesita is more than just a place to live. The campus offers services ranging from Head Start to mental-health counseling. Banks will offer classes in personal finance. Fitness and wellness classes are planned, and A New Leaf aims to bring in other programs to address residents' needs and problems.

Units range in size from efficiency apartments to three bedrooms. "Every unit has a patio," Taj said, and some two-story apartments have as many as four.

The architecture contrasts sharply with the surrounding streetscape, which consists mostly of decades-old auto-related businesses and trailer parks.

In keeping with Mesa's design standards for transit-oriented development, the setback from Main Street is minimal. The white-and-gray exteriors have neon-hued accents.

"We wanted to be different, we wanted to be bright, we wanted to be noticeable. We want people to know what this is," Taj said.

Taj hopes La Mesita — the first transit-oriented project along Mesa's rail line — will help spark a makeover for the neighborhood.

"We want to revitalize the area because we want people to come here and stay here," she said. "It's going to be be a community where people can put roots down."

The apartments now opening came with a $15 million construction price.

Two more phases are planned. Construction begins this spring on 16 units of emergency homeless shelter, whose $3 million cost will come from $1.5 million in federal grants funneled through Mesa and from a philanthropic fund drive.

A New Leaf has applied for another round of tax-credit financing for Phase 3, which will be 30 apartments for people who have been chronically homeless.

Mike Hughes, president and CEO of A New Leaf, recalled a tense meeting in late 2010 with a City Council committee chaired by Dave Richins.

Hughes had asked Mesa for $750,000 in federal grant money to fix La Mesita's plumbing. The committee balked, and Richins told Hughes to quit trying to patch up the old motel.

"I think he was right and I'm glad he was looking out for us," Hughes said as The Republic toured the new complex.

Mesa has been deeply involved in La Mesita for years.

Mesa used a federal grant to buy the property in 1991 and A New Leaf — then known as Prehab of Arizona — opened the shelter that same year.

Mesa deeded the property to A New Leaf in 2008.

Mesa gave A New Leaf a $500,000 interest-free, 20-year loan to help with Phase 1, and also spent $1 million to buy land owned by the agency so it could expand Monterey Park. That money went into the La Mesita project.